Answer:
Explanation:
When a lightning bolt travels from the cloud to the ground it actually opens up a little hole in the air, called a channel. Once then light is gone the air collapses back in and creates a sound wave that we hear as thunder. The reason we see lightning before we hear thunder is because light travels faster than sound!
Answer:
They can travel in a vacuum.
Explanation:
» Only electromagnetic waves travel through vacuum. The other mechanical waves require a material medium to travel.

Answer:
The resultant velocity is 
Explanation:
Apply the law of conservation of momentum

Where
is the mass of the Luxury Liner = 40,000 ton
is the velocity of Luxury Liner = 20 knots due west
mass of freighter = 60,000
is the velocity of freighter = 10 knots due north
Apply the law of conservation of momentum toward the the west direction

So the equation would be

Substituting values

Where
the final velocity due west
Making
the subject


Apply the law of conservation of momentum toward the the north direction

So the equation would be

Where
the final velocity due north
Making
the subject


The resultant velocity is



Answer:
77.88 lbm/ft³
Explanation:
Given,
Specific gravity, SG = 1.25
Density of water, ρ = 62.30 lbm/ft³
density of the fluid =
= S.G x ρ_{water}
= 62.30 x 1.25
= 77.88 lbm/ft³
Density of the fluid is equal to 77.88 lbm/ft³
Answer:
P = 0.0644 atm
Explanation:
Given that,
The pressure of a sample of gas is measured as 49 torr.
We need to convert this temperature to atmosphere.
The relation between torr and atmosphere is as follow :
1 atm = 760 torr
1 torr = (1/760) atm
49 torr = (49/760) atm
= 0.0644 atm
Hence, the presssure of the sample of gas is equal to 0.0644 atm.